In a microwave-assisted magnetic recording (MAMR) head manufactured by aligning a main magnetic pole and a spin torque oscillator (STO) by self-alignment, the positions of the main magnetic pole and STO must be aligned. However, if the main magnetic pole is processed by ion beam etching (IBE) together with the STO by self-alignment, an etched high-Bs main magnetic pole material is redeposited on the sidewalls of the STO. The redeposited main magnetic pole material significantly suppresses the oscillation of the STO. On the other hand, if the redeposited main magnetic pole material is completely removed by IBE, damages to the STO layer and the shape deterioration of the STO are significant.